Keratin is present in

Options

A. Blood
B. Hair
C. Milk
D. Muscles

Answer

To determine where keratin is present, we can analyze the options provided: blood, hair, milk, and muscle.

### Step-by-Step Solution:

1. **Understanding Keratin**:
- Keratin is a type of protein known for its protective qualities. It is less prone to scratching or tearing compared to other proteins in the body.

2. **Analyzing the Options**:
- **Blood**: Blood contains various proteins such as fibrinogen, albumin, and globulin, but keratin is not one of them.
- **Hair**: Keratin is a major component of hair, making it strong and resilient.
- **Milk**: The primary protein found in milk is casein, not keratin.
- **Muscle**: Muscles primarily contain contractile proteins such as actin and myosin, and do not contain keratin.

3. **Conclusion**:
- Based on the analysis, keratin is specifically present in hair. Therefore, the correct answer to the question is **hair**.

### Final Answer:
Keratin is present in **hair**.

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